250-million-year-old bacteria?!

My article was called "Rock of Ages", and it talked about a microbe that was found trapped in some fluid in a 250-million-year-old formation of salt in New Mexico! This microbe was given the name Bacillus, and was then changed to. Virgibacillus species 2-9-3. There was a lot of skepticism because biological chemists doubted that nuclei acids could last that long, an even if it had managed to hibernate as a spore, it's DNA should've broken down in 250 million years from the barrage of earths natural radiation over the extended period of time. It was argued that more recent fluid had found it's way into the rock, and that it's DNA sequence was far too similar to that of a modern strain. So eventually a team from Nature magazine joined a team from Geology to test the theory that the fluid is newer than the surrounding rock. So they took the temperature of the same part of rock the original sample came from and the temperature ranges from 63-99 degrees Fahrenheit, a distribution that suggests seasonal climate change. They also did a test to measure the ions in the fluid to compare it to the seawater changes over time, and the sample matched the ions of the Permian period. The last criticism is that of the bacteria DNA being the same as that of a strain from the Dead Sea, but a member of the team challenged the models that predict that these strains came about tens of thousands instead of millions of years ago.
As for questions I have, one is that if there's another test that would prove the validity of Virgibacillus' age. I also wonder if, like the article says, if the strain found in the Dead Sea really didn't come about millions of years ago. This article was really interesting to me specifically because I'm surprised that there is no set method for determining the age of microbes.